PDCD1 and neoplasm: The results showed that the expression of TIGIT, PD1, LILRB4, LAG3, CTLA4, CD200R1 and BTLA was the highest in tumor tissues, the expression of LAIR1 and HAVCR2 in tumor tissues was lower than that of adjacent tissues but higher than that of normal tissues, and the expression of CD160 was the lowest in tumor tissues.